Hydraulic couplings



June 20, 1961 R. c. zElDLl-:R ETA. 2,989,004

HYDRAULIC coUPLINGs Filed Feb. 1, 195e 5 sheets-sheet 1 Fg@ ci?! C 5 f@ @42W @QL- R. c. zElDLr-:R ET AL 2,989,004

June Z0, 1961 HYDRAULIC COUPLINGS m m i@ fm d 5 Q y w R. c. zr-:IDLER ETAL 2,989,004

HYDRAULIC coUPLINGs 5 Sheets-Sheet 3 June 20, 1961 Filed Feb. 1, 195e 0 6420 wywwmzm/f//a 5 Sheets-Sheet 4 EX/T EGE i l R. C. ZEIDLER ET AL HYDRAULIC COUPLINGS TA/L//VG 0R 9. w a. 6 M 7N, al u m /0 @.N 5m A an 4. D E 5 2 June 20, 1961 Filed Feb. 1, 195e LEAD/IVG 0f? ENTRA/VCE EDGE 0 66420664206f/o4m3 3 3 3 3 3 2 2 2 2 2 N 1S K wwwrun@ SSS X bi v wbwmk k kkuxh June 20, 1961 Filed Feb. l, 1956 R. C. ZEIDLER ET AL HYDRAULIC COUPLINGS 5 Sheets-Sheet 5 r2,989,004 Patented June 2,0, 1961 United States Patent Oliice HYDRAULIC 'COUPLINGS `Reinhold C. Zeidler, William A. Barnes, and Daniel W.

This invention relates to hydrodynamic couplings and more particularly to such couplings of the type having relatively rotatable members providing a closed uid circuit and utilizing thin metal vanes to control the flow of Huid. v

Hydrodynamic couplings employ vanes in the different relatively rotatable vaned members comprising an impeller or pump, a turbine or runner, and, in the torque conversion type, a stator or reactor, to control the ilow of uid in a toroidal uid circuit formed by the members, the vanes being formed, for example, of thin sheet metal stampings. It is desirable to use thin sheet metal vanes for hydrodynamic couplings of the torque conversion type, or hydraulic torque converters, as these vanes permit the largest possible number of closely spaced vanes to be used in the vaned members, which allows the couplings to develop practically all of the theoretical maximum head of the operating fluid circulating in the couplings while insuring the correct uniform control and guidance of the lluid ow through the conventional toroidal path provided by the vaned elements of the coupling. A further feature is that thin metal vanes are of lightweight and are readily formed as stampings having the desired curvatures for controlling the uid llow for torque multiplication. In hydraulic'torque converters, each of the vaned members usually comprise curved thin metal vanes extending between a shell or supporting member and a core ring, the vanes being secured thereto, for example, by welding or mechanical inter-locking connections, to provide fluid passages in the members.

In the operation of such hydraulic torque converters, two problems have been bothersome, namely, an annoying whistling sound or noise objectionable to the operator of machines, such as automobiles, embodying hydraulic torque converter transmissions and secondly the inability to obtain the efliciency indicated by vane design calculations. An analysis of the noise has been identified as being of two types attributable to cavitation and whistle. Concerning the cavitation noises, it has been found, in the operation of hydraulic torque converters, the thin metal vanes are subjected to shock from the flowing lluid during certain stages of torque multiplication,-when the fluid flowing from the passages of one of the vane members encounters the vanes of another vane member at an awkward angle producing a churning action of the fluid and decrease in lluid velocity and this hydraulic phenomenon, or cavitation, is caused by the local vaporization of a liquid because of local pressure reductions due to dynamic action and is characterized by the formation of vapor pockets in the interior or on the boundaries of `a rapidly moving stream of uid. This problem has been greatly alleviated by considerably increasing pounds per square inch of the lluid pressure in the torque converter by a pump circulating the fluid through the torque converter which eliminates the cavitation noise as far as the car operator is concerned. The whistling problem appears `to result from a disturbance in the ow of the iluid at the leading and trailing edges of the vanes and it has been determined that the whistling sound was increased slightly wit-h the change in higher pressure oi fluid in the torque converter and, for example. becomes evident at around 80() r 1000 engine r.p`.m. when a start `is made from a standing position of the car. This whistling noise is of short duration and varies in intensity with different torque converters and frequently is shrill and of an intensity to become very annoying to the operator of the automobile. i

It isan object of the invention to provide vaned elements of hydraulic couplings embodying vanes formed so as to be less vcapable of producing noise, particularly, whistling noise, annoying to the operator of a machine embodying the hydraulic coupling.

Another object of the invention is to provide new and improved vanes for use in hydraulic couplings, each vane being of thin sheet metal with the leading and trailing` edge portions of the vanes being formed to prevent or substantially reduce disturbance in the llow of the iluid at these edge portions of the vanes during operationl of the torque converter to eliminate whistling noises during operation of the torque converter.

Another object of the invention is to provide new and improved vanes for use in hydraulic torque converters, each vane being of curved thin sheet metal and having the leading and trailing edge portions of the vanes provided with chamfers to eliminate noises and, particularly whistling noises, in the operation of the torque converter.

Another object of the invention is to provide new and improved vanes for use in hydraulic torque converters, each vane being of curved thin sheet metal having the leading and trailing edge portions of the vanes provided with chamfers to prevent disturbance in the flow of the Auid at the leading and trailing edge portions of the vanes during operationrfor effecting a substantial increase in performance of the torque converter.

A further object vof the invention is to provide a meth- 0d of making vanes for hydraulic couplings eifective to eliminate noises and to substantially increase the performance of the fluid couplings during operation of the couplings.

The invention consists of the novel constructions, arrangements and methods to be hereinafter described and claimed for carrying out the above stated objects and such other objects as will appear from the following description of certain preferred embodiments illustrated with reference to the accompanying drawings; wherein:

FIGURE l is a longitudinal section through a hydraulic torque converter including pump, turbine, and stator members having vanes illustrating a preferred embodiment of the invention.

FIGURE 2 is a diagrammatic illustration of the pump, turbine and reaction member vanes of the torque converter of FIGUR-E l and showing the curvatures thereof along the middle stream line or main ow line with a vectorial representation showing the relative lluid ow angles at stall and during different portions of 'the torqueconverting range and the coupling range of the torque converter.

FIGURE 3 is a sectional View through the radially central portion of any of the bladed elements of a torque converter lookin-g inwardly toward the converter center showing a vane having leading and trailing edges formed in accordance with prior -art practice, a substantial portion of the vane being broken away to more clearly illustrate the leading and trailing edge portions of the vane;

FIGURE 4 is a graph illustrating the performance characterstics of the torque converter having pump, turbine and stator vanes provided with the curvatures of FIGURE 2 and with leading and trailing edge portions of the vanes fformed as shown in FIGURE 3;

FIGURE 5 is a View similar to FIGURE 3 showing a vane having its leading and trailing edge portions formed in accordance with a preferred embodiment of the invention, a substantial portion of the central region of the vane having been removed to more clearly illustrate the leading and trailing edge portions of the vane;

FIGURE 6 is a graph illustrating the performance characteristics of a torque converter having the pump, turbine and stator vanes provided with the curvatures of FIG- URE 2 and with the leading and trailing edge portions of the vanes formed in the manner as shown in FIG- URE Y FIGURE 7 is a view of a vane similar to FIGURE 5 illustrating a modification of the vane shown in FIG- URE 5;

FIGURE 8 is a view similar to FIGURE 5 illustrating lanother modification of the vane shown i-n FIGURE 5;

FIGURE 9 is a view similar to FIGURE 5 of a Vane illustrating another embodiment of the invention;

FIGURE 10 is a graph illustrating the performance characteristics of a torque converter having the pump, turbine and stator vanes formed in a manner illustrated in FIGURE 9;

FIGURE ll is a view similar to FIGURE 5 of a vane illustrating a modification of the vane shown in FIG- URE 9; and

FIGURES l2 to 14, inclusive, are views similar to FIGURE 5 which illustrate still further and different vanes embodying the invention.

The drawings are to be understood to be more or less of a schematic character for the purpose of disclosing typical or preferred forms of the improvements which are contemplated herein.

Referring now to FIGURE l for a detailed description of the hydrodynamic coupling ofthe torque converting type as shown, the coupling comprises a varied element or a pump or impellcr 10, a vaned element in the form of a turbine or runner 11, and a vaned reaction element or stator indicated at 12. The left side in this ligure faces the front of the vehicle in which the torque converter is disposed and the impeller, turbine and stator-when rotating-tum in a clockwise direction when viewed from the front of the vehicle in any normal automotive installation. In this application it is yassumed that the converter is disposed in such `a normal automotive installation. The impeller 10 comprises a semi-toroidal shell 13 having a flange 14 at its outer edge, the flange 14 being secured to a driving plate 15 connected to an engine-driven shaft 16. The impellcr further comprises a core ring 17and vanes 18 formed of thin sheet metal and extending between the `core ring 17 and shell 13, the vanes 18 having a plurality of tabs on their outer curved margin received within slots in the shell 13 as `clearly shown in FIGURE l and the inner arcuate margin of each vane is provided with a tab which extends through the core ring 17 and overlaps and engages the inner su-rface thereof. The turbine 11 is also provided with a semi-toroidal shell 19 and core ring 20, and `a plurality of vanes 21 extending between and having tabs on each of their outer and inner arcuate margins receivable within slots in the shell 19 and the core ring 20 to maintain the shell, core ring and vanes in assembly. The stator 12 comprises an annular shell 22 and a core ring 23, with a plurality of vanes indicated at 24 extending lbetween the shell 22 and core ring 23, the vanes 24 having tabs around and received within slots in the annular member 22.

Hub 2S of the impellcr is rotatably mounted on a stationary cylindrical sleeve 26. Theturbine 11 has la hub 27 splined to the shaft 28 extending through the sleeve 26. The stator 12 has a hub 29 rotatably mounted on spaced annular bearing members 30,v 30 and between the hub 29 and a` collar 31, splined to the stationary sleeve 26, a one-way brake indicated at OW.

The hydraulic torque converter functions to' multiply torque between the engine-driven shaft 16 and the driven shaft 28 connected to the turbine 11, the vanes of the impeller 10 imparting energy to a body of fluid circulating, as indicated by the arrows, in a toroidal path within the torque converter, the turbine 11 receiving energy from the 4 fluid, and the stator 12 being held from rotation by the one-way brake OW to provide the necessary reaction for multiplication of torque by the converter. As is wellknown in the art, Ichanges in the direction of the lluid flowing from the turbine to the stator during decreasing torque multiplication of the torque converter will eventually effect rotation of the stator with the impeller and turbine, Le. upon the fluid being directed against the backs of the vanes of the stator, the one-way brake will release the stator for rotation.

The component parts of the turbine, namely, the vanes 21, the core ring 20 and the shell 19 are formed of thin sheet metal, and this is also true of the core ring 17 and vanes 18 of the impeller, the shell 13 of the impellcr being formed of heavy sheet metal stamped to provide the toroidal configuration shown. The stator 12 has its vanes 24, the annular member 22 and core ring 23 formed of sheet metal.

For the purpose of a clear understanding of the invention, reference is made to FIGURE 2 illustrating a typical example of fluid flow conditions between the impeller, turbine, and stato-r vaned elements of the hydraulic torque converter. FIGURE 2 diagrammatically illustrates the pump, turbine and reaction element vanes showing the curvatures along the middle stream line or the main flow line and illustrating pictorially the changing angles of fluid flow 4from one to the other of the vaned elements or members and showing the relative fluid flow angles at stall and during different portions of the torque-converting range and the coupling range of the pump, turbine and reaction element vanes shown in FIGURE 1. In the operation of the torque converter, the fluid flows in a circuitous path from the impeller toward the turbine which in turn directs the fluid towards the stator which causes the fluid to flow into the impellcr in the direction of the arrows, as indicated in FIGURE 1 to provide different torque multiplication ratios varying from the largest torque multiplication ratio at the time the turbine is standing still or rotating slowly up to the coupling point of the torque converter when the otherwise stationary stator rotates and the torque converter then operates as a fluid coupling at a substantially one-to-one ratio. In FIGURE 2. the direction of the fluid flow from one vaned element to the other is indicated as the Stall condition and affords maximum torque multiplication of the hydraulic torque converter and it will be seen that the angles of the fluid flow from one vaned element to the next adjacent vane element changes as indicated by the arrows up to and including the Coupling Point when the fluid strikes the backs of the vanes of the stator to cause the one-way brake OW to release so that the stator rotates with the impellcr and turbine to provide a substantially one-toone ratio. As the performance characteristics of a torque converter are enhanced by the smooth flow of the fluid through and between and engaging the vanes of the vaned elements, it is of primary importance that any churning yaction or disturbance in the flow of the fluid into and through the passages of the vaned elements should be avoided. In addition, this churning action or disturbance in the flow of the fluid may cause undesirable noise objectionable to the operator of the machine, such as an automobile, in which the hydraulic torque converter may be used. It has been found that where vanes, such as those shown in FIGURE 3, are used in all the vaned elements or either the impeller, turbine and stator of a torque converter, a high shrill whistling sound or noise often results from a disturb-ance in the flow of the fluid at the leading edges of the vanes by the fluid flowing at such an angle from one of the varied elements so as to strike the blunt end indicated `at N in FIGURE 3 at the leading edge of the vane and also, after the fluid flows along the vane, the resultant discharge at another angle from the trailing edge of the vane effects a further disturbance of the flow of the fluid. It has been determined that such disturbances produce a whistling sound which pressure side of the vane.

mayvary in `intensity, and frequently be in the form of a high pitched shrill whistle which is annoying to the-opera-i tor :ofthe automobile.

nThe presentinyention is' directed to the formation of vanes of thin sheet metal of hydraulic uid couplings audltorque 1converters having the leading and trailing edge portions ofthe vanes formed in a manner to eliminate or substantially minimize the disturbance of the flow of the fluid at the, leading and trailing edge portions of the vanes for the purpose of obtaining a substantial increase in the perfomance of the torque converter as well as to completely eliminate, so far as the operator is concerned, the whistling sound or noise, during operation of the torque converter. For this purpose, in the preferred embodiment of the invention, the vanes of' the impeller, turbine and stator, prior to their final forming, are chamfered in their hat state and are formed `as shown in FIG- URE S to substantially increase the performance of the torque converter while eliminating yany ywhistling sound, in the 'operation of the torque converter.

More particularly, the vanes of the impeller, turbine and stator are each formed of thin sheet metal, such as steel stampings, having their liquid entrance and exit portions provided with a chamfer S extending to their leadingand trailing edges L and E so as to produce a long chamfer almost knife edge sharp on the low pressure side of the vane indicated at C b -indicating the high It will be observed that each of the vanes is of thin sheet metal Aand are' stamped from a large sheet of uniform thickness. VThe forming of the trailing and leading edge portions of the vane vas shown in FIGURE 5, provides chamfers S inclined at angles from the parallel flat sides or planes of the body portion P of the vane with the chamfer S gradually decreasing in' thickness from the body portionP toward the particullaredge of the vane:

TheV bestl method for the forming of the vanes to produce the chamfered surfaces S on the leading and trailing edge portions ofthe vanes is'to initially utilize a` flat sheet of metal and to stampthe vanes from this` Asheet of metal; secondly, to coin the two trailing and leading edge portionsA of the individual vanes to produce the chamfers S;,and thirdlyto position the hat vanes in a die to form the vanes with theproper curvatures for obtaining the desired" torque multiplication ratio characteristics ofthe vanes. Tlhe coining operation increases the length of the vane approximately .03,0 in a vane having a thickness of .036, FIGURE 5 illustrating, in dotted lines, the leading and trailing edges of the blank' vane before coining and nsolid lines, the shape of the edges after the coining opvera-tion has been completed. It has been found that where the sheet metal is a hard material, the leading and trailing;` edges will finish up with a relatively square edge, as shown in FIGURE ,5, while the softer materials will'tend to bulge the end of the Vane to form a desirable crown or radius, as shown at a in FIGURE 7. `Accordingly, the example `of the vane shown in FIGURE 5 has been formed lof a relatively hard material and it isnoted'that theedge of the vane isapproximately square.

Results of experimentaltests indicate that the thickness t of the chamfered leading and -traihng edge portions can satisfactorily ,be made to between .010 inch and .020.inch when the' thickness of the' body of the vane indicated at T varies bet-Ween .036 inch and .O50 inch. This comparison of the thicknessv of the vane as'indicated at Tand` the thickness at thechamfered edge of thevane indicated at t establishes'a ratio between the nominal thickness of the material as indicatedA at and the thickness of theV material at the chamfered edge as indicated` at' t, and whichy isefective' to insure 1the correct calculatin of the thickness of the chamfered edge portions with respect to the nominal thickness of the material as indicated atT in the. design 0f all, 0lfflu converters ,utilizing sheet metal vanes. This ratio may be' arbitrarily called a sharpness ratio and is equal to T/t. It has been found that'this ratio will varyI from 1.5 to l, to about 9.0 to 1 depending-.on the initial thickness of'metal and the reduction in the thickness at the edge. The length of the chamfer andthe reduction in thickness determines the angle of the chamfer. If there is achamfer on only one ,side of the vane as shown inl FIGURE 5, the angle alpha has the sine of y T-t whereas, if the chamfer is appliedto both sides ofthe vane as 'will be later described and as shown in FIGURES 9Y and 11,` the'an'gle alpha is equal to 2 times (x) the sine of T-t l On the'basis of the above formulas, the chamfered portions ofthe vanes havevaried all the way from about 5 nto 30 for the included angle. `In experimental testing fof vanes, the angle of the chamfer has been around 10, but it has been proven that this angle could vary from about 6 to 14 depending upon the sharpness ratio andV the `thickness of the stock, with this Variation in the degree of angularity being considered to be satisfactory for atmanufacturing tolerance'.

in formingthechamfers on the vanes experimentally, the chamfers have been milled 'on the vanes. This is an expensive operation, although providing excellent results. Forming the chamfers by coining the leading and trailing edge portions of the vanes is inexpensive in production and is entirely satisfactory in providing the desired results.

Referring to the graphs illustrated in FIGURES 4 and 6, the'graph of FIGURE 4 illustrates the characteristics of a torque converter having vanes of uniform thickness and including the blunt Aleading and trailing edges as indicated at N in FIGURE 3 in accordance' with conventional practice in the hydraulic torque converter art. 'Ihe graph of FIGURE-6 illustrates a hydraulic torque converter having vanes identical in curvature to that of the torque converter having the characteristics illustrated in FIGURE 4, however, with each vane being chamfered at the leading and trailing edge portions L and Ev thereof on ythe low pressure side c from the thickness of .036 inch uniform dimension of the body portion P of the Vane and tapering at the leading and trailing ends of the vane as indicated in FIGURE 5. A torque converter having vanes with chamfered leading and trailing edge portions on the low pressure side was found to have the performance characteristics reilected in FIGURE 6 and to be effective to eliminate whistling noise or sound in the torque converter at all stages 'of the torque multiplication and coupling ranges of the torque converter during the operation of the torque converter. It will be apparent from a comparison of FIGURES 4 and 6 that the ehiciencyl characteristics of the torque converter of FIGURE 6 was raised from between 88 and 8.9% to 91% in comparison tothe torque converter of FIGURE 4. Also, FIGURE 6 shows that the torque ratio at stall was increased in comparison to the torque ratio at stall of the torque converter of FIGURE 4 and that the coupling point was extended by about .86 to .88. It will thus become apparent that the chamfers on the vanes in accordance with the above description and as illustrated in FIGURE 5 is effective to not only eliminate whistling noise during the operation of the torque converter but also to provide substantial increases in the performance characteristics of the torque converter as reflected by a comparison of the graphs of FIGURES 4 and 6.

While it is believed that the chamfer on the low pressure side lc of the vane as indicated in FIGUREA 5' is desirable Yto obtain'optimum results, experiments appear to" indicate that little diierence in results are obtained between chamfers on the low pressure side of the vane asshown in FIGURE in comparison to chamfers on both-the low and high pressure side as shown in FIGURE 9; 4Howeven/evidence has been determined from these experiments that various configurations of chamfers at the leading and -trailing edge portions of the vanes may show improved results, for example, such as the chamfers on these portions of the vanes as shown in FIGURES 8 and 11, wherein each tapered surface may be slightly crowned or otherwise shaped to improve the ow of the iiuid instead of being flat as shown in FIGURES 5, 7, and 9. Referring to FIGURE 8, it Will be seen that the chamfer or tapered surface Q is slightly crowned which is believed to improve the ow of the uid along the vane and, in FIGURE 11, the low pressure side c and the high pressure side b provide crowned chamfered surfaces converging toward the ends of the vane. It is believed a satisfactory manner of denoting the angle for this character of the tapered surfaces shown in FIGURES 8 and 11, is to use a reference line through intersecting points with one end of the line passing through the point x representing the intersection of the crowned surface and the radius of edge caused by displacement of metal, while the other end would pass through the point y representing the intersection between the crowned surface and the nominal flat surface of the body of the vane. The formulas for determining the included angle would be identical to the formulas referred to above in determining the included angles of FIGURES 5 and 7.

FIGURE 10 is a graph illustrating the performance characteristics of a hydraulic torque converter having curvatures of the vanes identical with that of the torque converter having the performance characteristics indicated in FIGURE 4, but the torque converter represented by the graph of FIGURE l0 has the entrance and exit portions provided with chamfered surfaces on both the low and high pressure sides as shown in FIGURE 9. A comparison of FIGURES 4 and 10 clearly reveals that the torque multiplication ratio at stall of the torque converter of FIGURE l0 has been considerably increased, the coupling point having been extended from approximately .86 to .88 and the efficiency raised from 88% to 91%, thus clearly illustrating that the torque converter having chamfered surfaces on its high and low pressure sides at its entrance and exit portions affords a substantial increase in the desirable performance characteristics of a'torque converter over that of the hydraulic torque converter with the entrance and exit portions being of the same uniform thickness as the body portion of the vanes as shown in FIGURE 3 and embodied in a torque converter graphically illustrated in FIGURE 4.

FIGURE 12 illustrates a modification of the vanes shown in FIGURE 5, wherein the leading edge portion L of the vane is chamfered on its low pressure side C with the chamfer or inclined surface S and the trailing edge portion E is provided with a chamfer M on the high pressure side.

FIGURE 13 illustrates a further modication of the vane shown in FIGURE 9, wherein the leading edge portion of the vane is formed with chamfered surfaces S and V on opposite sides of the leading edge L thereof, namely, on its low pressure and high pressure sides c and b respectively and the trailing edge portion E of the vane is provided with a tapered surface m on its high pressure side.

FIGURE 14 illustrates a still further modification of the vane shown in FIGURE 9 and wherein the leading edge portion L of the vane is provided with chamfered surfaces S and V on the low and high pressure sides C and b thereof respectively and the trailing edge portion E is provided with an inclined surface Z on the low pressure side thereof.

It is believed that tests will clearly determine Vwhich particular type of chamfer on either or both the high,

low pressure sides of the vanes for a particular vane is best suited 4for a particular vane and particular torque converter. Factors in determining which of the different chamfered surfaces illustrated in FIGURES 7, 8, 9, 1l and 12 to 14, inclusive, will be most useful and the application of where to employ the chamfer or chamfers on the vane, as reflected in these views, will be the design point, the vane angles at the leading and trailing edge portions of the entrance and exit of the vanes, and the kind of performance desired from a torque converter. For example, tests may prove that for a given design of converter the best results are obtained when only the low pressure side of each vane is provided with chamfers at the leading and trailing edge portions thereof as shown in FIGURE 5 but for another design of converter the optimum results may be obtained when both the low pressure and high pressure sides at the leading edge portion of the vanes are provided with chamfered surfaces and a chamfered surface is provided at the trailing edge only on the high pressure side b as shown in FIGURE 13. These tests should indicate and reveal the combinations that will be most beneficial.

It is important that in the design of stamped steel vanes having the chamfered surfaces as relected in the figures of the drawings that the sharpness ratio be calculated as the ratio of the thickness of the body of the vane to the thickness of the vane at the chamfered edge thereof and it is believed that the most useable ratios lie within the limits of 1.5 to 9.0 to l. In combination with this sharpness ratio, it will be necessary to consider the included angle of the tapered surfaces comprising the chamfered portions of the vane and it is believed that the most beneficial angles will lie between the limits of 5 and 30. It will be apparent that the tapered surfaces of the vanes, and defined by the chamfers, need not be flat as shown in FIGURES 7 and 9, for example, but may be advantageously crowned as shown in FIGURES 8 and l1. It will be noted that the chamfered edges of the vanes as shown in FIGURES 5, 7, 8, 9 and ll to 14, inclusive, and indicated at a in FIGURE 7, are caused by displacement of the metal and which edges may automatically come out relatively square or with appreciable radius because of being influenced by the hardness and type of material used. It is within the contemplation of the invention that a definite radius is desirable and which may be able to be produced at will. It may also be desirable and is within the contemplation of the invention that more than one type of chamfered surface may be employed in a single blade as reected in the various views of the drawings and that several variations of the chamfered surface may be employed in the vanes provided in a single torque converter.

It will also be apparent that, in providing a solution for the whistling noises resulting from a disturbance in the ow of the luid at the leading and trailing edges of the vanes during operation of the torque converter, the elimination or substantial reduction of the disturbance in the flow of the fluid at these edges of the vanes has also been effective in eliminating any disturbance to the fluid flow at these edges of the vanes to substantially increase the eficiency indicated by design calculations of the vanes.

Where the term coining is used in this application, it refers to cold working of metal under pressure to alter its shape.

While this invention has been described in detail with respect to certain forms of embodiments, it will be apparent to persons skilled in the art, after understanding the improvements, that various changes and modcations therein may be made without departing from the spirit. or scope thereof. It is aimed in the appended claims to cover all such changes and modifications.

, 1. AA liquid flow-controlling vane for a fluid coupling device formed ofqsolid sheet metal having a high press ure side and a low pressure side and comprising a body portion of substantially uniform thickness, and spaced liquid entrance and exit portions having leading and trailing edge portions terminating at the ends of the vane; and a chamfer on one of the leading and trailing edge portions at one of the low and high pressure sides of the vane and gradually decreasing the thickness of said one edge portion yfrom the juncture of said chamfer with the body portion to the associated end of said one edge portion, the ratio of the thickness of the body portion to the thickness at the end of said one edge portion being between 1.5:1 and 9.0:'1.

2. A vane as dened in claim 1 Iwherein the included angle between the chamfer on said one side of said one edge portion and the other of the high and low pressure sides of said one edge portion is between 5 and 30.

3. A vane as dened in claim 1 wherein the end of said vane terminating said oneedge portion extends arcuately transversely of the vane.

4. A vane as defined in claim 1 wherein the charnifer on said one edge portion is formed to provide a convex surface.

5. A vane as defined in claim 1 wherein the chamfer is on the low pressure side of the vane.

6. A liquid How-controlling vane for a iluid coupling device -formed of solid sheet metal having a high `pressure side and a low pressure side and comprising a body portion of substantially uniform thickness, and spaced liquid entrance and exit portions respectively having leading and trailing edge portions terminating atthe ends of the Vane; and a chanifer on one of the low and high pressure sides of one of said leading and trailing edge portions gradually decreasing the thickness of said one edge portion from the juncture of said chamfer with said body portion to the end of the vane terminating said one edge portion, the ratio of the thickness of the body portion tothe thickness at the end of the vane terminating said one edge portion being equal to T/ t, and the included angle defined by the chamfer and the other of said sides of said one edge portion having the sine of wherein T is the thickness of the body portion, t is the thickness of the end of said one edge portion, and 1 is the length of the chamfer from its juncture with the body portion to the end of said one edge portion wherein said ratio is between 1.5 :1 and 9.0:1 and wherein said included angle is between 5 and 30.

7. A liquid Ihow-controlling vane for a fluid coupling device formed of solid sheet metal having a high pressure side and a low pressure side and comprising a body portion of substantially uniform thickness, and spaced liquid entrance and exit portions having respectively leading and trailing edge portions terminating at the ends of said wane; and chamfers on the low and high pressure sides of one of said leading and trailing edge portions gradually decreasing the thickness of said one edge portion from the juncture of said chamfers of said one edge portion with said body portion to the end of said one edge portion, the ratio of the thickness of the body portion to the thickness at the end of said one edge portion being equal to T/ t, and the included angle defined by the chamfer being equal to T-t 2(51ne of 2X 1 1G wherein T is the thickness of the body portion, t is the thickness at the end of said one edge portion, and 1 is the length of the chamfers from their juncture with the body portion to the end of said one edge portion wherein said ratio is between 1.5 :1 and 9.021 and wherein said included angle is between 5 and 30.

8. A liquid how-controlling vane for a uid coupling device formed of solid thin sheet metal having a high pressure S'ide and a low pressure side and comprising a body portion of substantially uniform thickness, and spaced leading and trailing edge portions, and chamfers on the low pressure side of said leading and trailing edge portions gradually decreasing the thickness of said leading and trailing edge portions from the juncture of said charnfers with said body portion to the ends of said edge portions, the ratio of the thickness of said body portion to the thickness at the end of said leading and trailing edge portions being between 1.5:1 and 9.0: 1.

9. A liquid flow-controlling vane for a uid coupling device formed of solid thin sheet metal having a high pressure side and a low pressure side and comprising a body portion of substantially uniform thickness, and spaced leading and trailing edge portions, and chamfers on the high and low pressure sides of said leading and trailing edge portions gradually decreasing the thickness of said edge portions to provide surfaces on each of said edge portions converging toward the ends of said vane, the ratio of the thickness of said body portion to the thickness at the end of said leading and trailing edge portions being between 1.5:1 and 9.0: 1.

10. In a fluid coupling device, a vane of solid sheet metal having a high pressure side and a low pressure side and comprising a body portion of substantially uniform thickness, and spaced liquid entrance and exit portions having leading and trailing edge portions respectively terminating at the ends of t-he vane, a coined chamfer on the leading and trailing edge portions of the vane at the low pressure side of the vane, said body portion of substantially uniform thickness being between 1.5 and 9.0 times the thickness of the blade at the end of said charnfered edge portions, the included angle between the chamfer on the low pressure side of said vane and the high pressure side of said vane being between 5 and 30.

References Cited in the tile of this patent UNITED STATES PATENTS 730,589 Weiss June 9, 1913 1,519,245 Fechheirner Dec. 16, 1924 1,600,690 Meyer Sept. 21, 1926 1,825,622 Kennedy Sept. 29, 1931 1,983,201 Rijswijk Dec. 4, 1934 2,306,639 Miller Dec. 2, 1942 2,306,758 Schneider et al. Dec. 29, 1942 2,365,354 Pennington Dec. 19, 1944 2,387,722 Dodge Oct. 30, 1945 2,496,496 Roth et al. Feb. 4, 1950 2,598,620 Swift May 27, 1952 2,696,171 Jandasek et al. Dec. 7, 1954 2,736,171 Stalker Feb. 28, 1956 2,745,352 Zeidler May 15, 1956 2,772,538 Ullery Dec. 4, 1956 FOREIGN PATENTS 414,518 Germany June 5, 1925 900,706 France Oct. 16, 1944 

